A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on π-stacking of the polymer backbone, which was retained in PTNT:fullerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 5% for >200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of >4% could be retained when thick active layers of 400 nm were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.

BibTeX @article{Kroon2014,author={Kroon, Renee and Diaz de Zerio Mendaza, Amaia and Himmelberger, Scott and Bergqvist, Jonas and Bäcke, Olof and Faria, Gregório Couto and Gao, Feng and Obaid, Abdulmalik and Zhuang, Wenliu and Gedefaw, Desta Antenehe and Olsson, Eva and Inganäs, Olle and Salleo, Alberto and Müller, Christian and Andersson, Mats R.},title={A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap Photovoltaics},journal={Journal of the American Chemical Society},issn={0002-7863},volume={136},issue={33},pages={11578–11581},abstract={A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on π-stacking of the polymer backbone, which was retained in PTNT:fullerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 5% for >200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of >4% could be retained when thick active layers of 400 nm were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.},year={2014},}

RefWorks RT Journal ArticleSR ElectronicID 202132A1 Kroon, ReneeA1 Diaz de Zerio Mendaza, AmaiaA1 Himmelberger, ScottA1 Bergqvist, JonasA1 Bäcke, OlofA1 Faria, Gregório CoutoA1 Gao, FengA1 Obaid, AbdulmalikA1 Zhuang, WenliuA1 Gedefaw, Desta AnteneheA1 Olsson, EvaA1 Inganäs, OlleA1 Salleo, AlbertoA1 Müller, ChristianA1 Andersson, Mats R.T1 A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap PhotovoltaicsYR 2014JF Journal of the American Chemical SocietySN 0002-7863VO 136IS 33AB A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on π-stacking of the polymer backbone, which was retained in PTNT:fullerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 5% for >200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of >4% could be retained when thick active layers of 400 nm were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.LA engDO 10.1021/ja5051692LK http://dx.doi.org/10.1021/ja5051692OL 30